X-Ray Crystal Structure of Betulin–DMSO Solvate

Abstract

Betulin is a lupane triterpenoid [lup-20(29)-ene3b,28-diol, C 30 H 50 O 2 ] showing high biological activity. This activity is supposed to be strongly affected by the molecular structure of its polymorphic forms. Different solvate polymorphic forms of betulin have aroused increasing interest as the possible anticancer agents of natural origin. X-ray diffraction was used to investigate crystal structure of (1:1) betulin-DMSO solvate. Title compound crystallizes in the orthorhombic P2 1 2 1 2 1 space group. Unit cell parameters are as follows: a = 7.0006(2) Å , b = 12.1623(3) Å , c = 33.6991(8) Å , Z = 4. Crystal packing and selected geometric parameters are described. It has been found that the hydrogen bonding and the dipole-dipole interaction between DMSO molecules play the major role in the formation of the crystal structure.

Betulin Phosphonates; Synthesis, Structure, and Cytotoxic Activity

“…Such ring conformation is similar to that found in solvates of betulin [27], betulinic acid [28], and 28-O-propynoylbetulin [2].…”

X-Ray Diffraction and Infrared Spectroscopy of N,N- Dimethylformamide and Dimethyl Sulfoxide Solvatomorphs of Betulonic Acid

“…Recent results presented by Drebushchak et al18 showed that the similar twist of the isopropenyl group was observed for the betulin–ethanol solvate, where the torsion angle C29–C20–C19–C21 was 88.64°. For betulin–DMSO solvate, the corresponding torsion angle was equal to −96.84° according to the results of Boryczka et al19 All quoted results suggest that the orientation of the isopropenyl group can be influenced by the kind of solvent used; however, this supposition needs more experimental work, especially in view of very limited amount of solvent used. The kind of solvent used for preparing the crystal and the role of H‐bonding in formation of different orientations of the isopropenyl group will be a subject of future work.…”

“…Different conformations of ring A are presented in Figure 4. The chair conformation of ring A was also observed for betulin–ethanol solvate,18 betulin–DMSO solvate,19 betulinic acid–benzyl ester,13 and 3β‐O‐feruloylbetulinic acid 14. All these compounds possess at the position C3 the hydroxyl group instead of the carbonyl group, which is present in BA.…”

Acrylated betulin as a comonomer for bio-based coatings. Part I: Characterization, photo-polymerization behavior and thermal stability

“…All other protons were distributed among numerous peaks located between 0.63 ppm and 2.00 ppm. Boryczka et al (2012) reported similar NMR analyses for betulin.…”